This invention relates to a new color display device.
Hitherto, among color display devices employing a liquid crystal, devices containing a dichroism dye as indophenol-blue in the liquid crystal are known. In such conventional devices, the color display is made as follows:
Light absorption by the dye molecule occurs when the molecular axis of the dye molecule is parallel to the electric vector of incident polarized rays, thereby displaying specific color of the dye. On the other hand, when the molecular axis of the dye molecule is perpendicular to the electric vector of the incident polarized rays, almost no absorption of light which passes through the dye occurs. In such a conventional device, the molecular structure of the dye is constant regardless of application or removal of the electric field to the liquid crystal.
Also, in the abovementioned conventional device, the color display is made by the absorption of polarized rays, and therefore, due to the observation of the polarized rays the color is not sufficiently pure and the view point is limited to a specified angle range.
In another conventional color display device, color has been displayed by employing a nematic liquid crystal and a polarizing prism or polarizing filter having a light axis perpendicular to that of the nematic liquid crystal. In such device also, due to employment of the polarized light, the color purity is not sufficient, and the view angle is limited.
In the abovementioned prior art the contrast of displays between electrified and non-electrified states reaches only about 10:1.